The 114th Illinois Infantry Regiment was an infantry regiment from Illinois that served in the Union Army during the American Civil War. Formed in September 1862, the regiment served in Ulysses S. Grant's Central Mississippi campaign, in the Vicksburg campaign, at Brices Cross Roads, at Tupelo, in the 1864 Missouri campaign, at Nashville, and at Spanish Fort. At Nashville, the unit participated in the decisive attack on Shy's Hill. In 1865, the regiment was reassigned as pontoniers. The regiment was mustered out in August 1865.